Mechanics | Relativity Answers

A helicopter pilot throws a ball downwards from an unknown height above the ground. The ball has an initial speed of 14.1 m/s. The ball hits the ground 9.2 s later. Find the initial height of the ball above the ground

A trolley,mass 5kg moves at 4m.s east across a frictionless horizontal surface. A brick of mass 1.5kg is dropped onto the trolley . Calculate the change in momentum of the 5kg trolley

The bone breaks if stress greater than 1.50 x 10 8 N/m 2 is imposed on it. (a) What is the

maximum force that can be exerted on the male humerus in the upper arms if it has a

minimum effective diameter of 5.87 cm? (b) If this much force is applied, by how much

does the 27.0-cm-long humerus stretched? Assume Young’s modulus for bone is 1.50 x

10 10 Pa.

A 75 kg. block of wood rest on the top of the smooth plane surface, whose length is 4 meters and whose altitude is 1.0 meter. How long will it take for th block to slide down to the bottom of the plane when released?

A ball is thrown from a tower 42 m. high above the ground with a velocity of 270 m/sec directed at 28⁰ from the horizontal. How long will the ball hit the ground?

which one of the following has the lowest viscosity

A. Water

B. Motor oil

C. Marble syrup

D. Glue

E. None of the above

a car is traveling up a hill that is inclined at an angle x above the horizontal determine the ratio of the magnitude of the normal force to the weight of the car when x=15degrees and x=35degrees

A 15-kg rock is dropped from rest on the earth and reaches the ground in 1.75 s. When it is

dropped from the same height on Saturn’s satellite Enceladus, it reaches the ground in 18.6 s.

(a) What is the acceleration due to gravity on Enceladus? (b) How long will it take for the

rock to reach the ground on Earth if it was released 100 m above the Earth’s surface? (c) in

Enceladus?

The tension in a string holding a solid block below the surface of a liquid (of density

greater than the block) is T0 when the container is at rest. When the container is given an upward acceleration of 0.250g, what multiple of T0 gives the tension in the string?

FIGURE 6 shows a 3.0 kg box sliding down with constant speed u = 1.2 ms-1 along a rough plank inclined at an angle 25o with the horizontal. Calculate the rate of work done by the frictional force on the block. (Given g = 9.81 ms-2)